updated 12:53 pm EDT, Mon May 6, 2013

Wrist-based tracker forgoes full display for five LEDs, no buttons

Fitbit has started shipping its first wrist-based activity tracker. The Fitbit Flex follows the Jawbone Up and the Nike FuelBand in providing tracking of activities and sleep patterns from the wrist, and like other Fitbit trackers in the entire range, is able to sync over Bluetooth 4.0 through iOS and Android devices, as well as using the provided Bluetooth dongle with a PC.

While being worn in a supplied wristband, the Fitbit Flex collects data in a similar way to a pedometer. Data is sent to Fitbit servers and can be accessed through the mobile app and the online Fitbit account, which also provides access to food logs and other items to help in fitness. In lieu of a display, the Fitbit Flex uses a series of LEDs to show how much of a predefined activity target has been accomplished, and while the device does not have any buttons, the target can be set through the Fitbit account, and switching modes can be done by tapping it a number of times.

In comparison to previous Fitbit devices, the Flex is said to be more water resistant to clip-on trackers like the Fitbit One, allowing it to be worn for far longer without risk of damage. Wearing it on the wrist instead of clipping it to clothing minimizes the risk of losing the Flex, or accidentally leaving it attached to clothes going through the washing machine, though its minimalist display may leave those wanting instant access to step counts or other details unsatisfied.